7-stable: Root mount problem (mpt, probing / timing related)
olli at lurza.secnetix.de
Tue Sep 20 17:08:42 UTC 2011
Gary Palmer wrote:
> On Tue, Sep 20, 2011 at 03:41:58PM +0200, Oliver Fromme wrote:
> > Hi,
> > I've updated a server with mpt controller to the latest
> > 7-stable (ok, it's 7-stable from last week). During the
> > boot sequence, the disk connected to the mpt controller (da0)
> > seems to be probed too late, i.e. just _after_ the kernel
> > tries to mount the root file system. It's just a fraction
> > of a second too late.
> > This is a screen shot of the situation:
> > http://www.secnetix.de/olli/tmp2/screenshot-boot.jpg
> > Of course, I can enter "ufs:da0s1a" at the rootmount prompt,
> > and the machine continues to boot fine. But this is a
> > server that should be able to boot unattended, so I need
> > this to be fixed.
> > What's the "official" way to fix this? I think someone else
> > had a similar problem some time ago, but a quick search of
> > the lists doesn't yield anything.
> > (BTW: Interestingly, the same machine boots fine without
> > hickup when booting 8-stable which is installed on another
> > Slice of the same disk. This could be just coincidence,
> > maybe the timing of probing is slightly different between
> > 7-stable and 8-stable.)
> Does increasing the
> loader tunable help at all?
It seems to help ... I have now rebooted three times with
scsi_delay set to 10000, and it worked so far (the problem
did not always occur before, so I have to try several times).
A value of 5000 was not sufficient.
First I had tried kern.cam.boot_delay, which seems to be
specifically for this kind of situation (according to the
description), but it didn't help at all. Even very large
values didn't help; I tried up to 30000.
I'm a little surprised that scsi_delay helps, but boot_delay
doesn't. I would have expected it to be the other way round.
Anyway -- Thank you very much for the hint!
Oliver Fromme, secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing b. M.
Handelsregister: Registergericht Muenchen, HRA 74606, Geschäftsfuehrung:
secnetix Verwaltungsgesellsch. mbH, Handelsregister: Registergericht Mün-
chen, HRB 125758, Geschäftsführer: Maik Bachmann, Olaf Erb, Ralf Gebhart
FreeBSD-Dienstleistungen, -Produkte und mehr: http://www.secnetix.de/bsd
"UNIX was not designed to stop you from doing stupid things,
because that would also stop you from doing clever things."
-- Doug Gwyn
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